Device for thermally insulating a building wall from the outside, and method for implementing such a device

ABSTRACT

A device ( 2 ) for thermally insulating a building wall ( 1 ) from the outside, being applicable in particular to walls and roofs, includes, starting from the wall, a layer ( 3 ) of impermeable rigid insulation, spacers ( 4 ) and a perforated rigid facing sheet ( 6 ) at a distance from the layer ( 3 ) of rigid insulation so as to form an air gap ( 7 ) between the facing sheet and the layer ( 3 ) of rigid insulation. A layer ( 8 ) of granular insulation ( 9 ) in divided form is contained in synthetic textile bags ( 10 ) placed in the air gap ( 7 ). A method for implementing such a device is also described.

The invention relates to a device for thermally insulating a building partition from the outside, in particular applicable to walls and to roofs, and more particularly such a device making it possible in addition to protect the partition and the insulation against deterioration by climatic assaults such as the sun, wind, snow, rain, etc. The invention also relates to a method for producing and implementing such a thermal insulation device.

There are two main techniques for ensuring the thermal insulation of a building. The first consists in providing—on the inner surface of the walls or the roof of the building—the placement of insulation materials such as glass wool, with a more or less significant thickness with regard to the desired thermal insulation coefficient. It is advisable, however, to leave an air gap between the inner surface of the wall or the roof and the insulation layer, and to cover this insulation layer, on its surface oriented toward the interior of the room to be insulated, by a covering such as plaster plates to maintain the insulation and to ensure correct finishing of the partition. In this case, the thickness of the insulation device impinges upon the living space of the rooms to be insulated.

The second technique consists in insulating the partitions of the building from the outside, i.e., to apply and attach a layer of insulation material to the outside of the walls and roofs. However, in this case, the insulation is subjected to climatic assaults that can make it deteriorate quickly.

This invention therefore has as its object to propose a device for insulating the partitions of a building from the outside that has an improved resistance to climatic assaults.

The invention also has as its object to provide such a thermal insulation device that is suitable for insulating walls or roofs without major modification of the device.

The invention also has as its object to provide such a thermal insulation device that can be installed above or instead of an existing roof.

In addition, the invention has as its object to provide such a thermal insulation device that has high thermal inertia.

The invention also has as its object to provide such a thermal insulation device that has an improved ecological impact.

To do this, the invention relates to a device for thermally insulating a building partition from the outside comprising:

-   -   A rigid and impermeable insulation layer comprising a first         surface, a so-called contact surface, suitable for being         attached to said partition, and a second surface, a so-called         outer surface, opposite to the contact surface,     -   A rigid and perforated cladding plate,     -   Spacers attached to said outer surface and adapted to hold said         cladding plate at a distance from the outer surface and to form         an air gap between said cladding plate and the outer surface of         the rigid insulation layer,     -   A layer of granular insulation between the rigid insulation         layer and the cladding plate,         characterized in that the granular insulation is in divided form         and contained in at least one synthetic textile bag.

The insulation device according to the invention uses a rigid and impermeable insulation layer formed by, for example, sheets of polystyrene or expanded polyurethane, with a thickness calculated based on the desired thermal resistance, which in turn is dependent upon the location of the structure. This insulation layer can be produced in one or more thicknesses made integral by bonding, for example, when the partition to be covered comprises rough spots where the first insulating thickness makes it possible to level out the surface and the second to produce a continuous cover. The insulation layer is attached by its contact surface to the partition to be insulated, directly or after a vapor-barrier screen is inserted depending on the nature of the partition to be insulated, if necessary attached to battens that are nailed onto, bonded to, or screwed into this partition. The installation of a rigid and perforated cladding plate, for example one or more plates of sheet metal that is perforated at a distance from the outer surface of the insulation layer, makes it possible to protect the former from the main climatic assaults. A perforated sheet-metal plate makes it possible for the air that surrounds both sides of the plate and preserves a surface temperature that is much lower than that of a solid plate to circulate when it is exposed to full sunlight. In addition, by selecting a sheet having a suitable number and dimensions of perforations, the insulation layer is shaded and removed from the influence of direct exposure to solar rays. For example, a perforation level on the order of 20% allows adequate air circulation while keeping 80% of the surface of the insulation in the shade. In addition, based on the latitude of the location of the structure and the exposure of the partition to be insulated, it is possible to calculate the optimal distance between the perforated cladding plate and the insulation in such a way as to limit the continuous exposure time of each point of the surface of the insulation layer. By way of example, a cladding plate comprising perforations of 5 mm and placed at 150 mm from the outer surface of the insulation layer makes it possible to limit to 7 minutes the continuous exposure of the insulation for a horizontal partition at the equator.

Thus, a rigid and perforated cladding plate makes it possible to limit the degradation of the insulation layer under the effect of exposure to sunlight. In addition, it makes it possible, thanks to its rigidity, to protect the insulation layer against the energy of the wind and the direct impact of rain or hail. The perforated cladding plate constitutes a protective layer in the case of snow by making it possible to support the weight of the snow layer, to minimize the risks of the layer sliding while making it possible to evacuate melt waters.

According to the invention, the thermal insulation device in addition comprises a granular insulation layer, in divided form, between the insulation layer and the cladding plate.

According to an advantageous characteristic, the granular insulation is a porous granular insulation, constituted by, for example, expanded clay balls or pumice stone gravel. By adding a layer of granular insulation in divided form between the insulation layer and the perforated cladding plate, the path of the water penetrating through the perforations of the cladding plate is modified. Direct streaming onto the insulation layer is minimized, and the time it takes for the water to rejoin the rain drainage circuit is lengthened, making it possible to minimize the clogging risks of the former and the risks of overflowing and flooding that could result therefrom. Thanks to this granular insulation layer in divided form, and particularly when it involves porous granular insulation, the thermal insulation device according to the invention makes it possible to adjust liquid flow rates by promoting water retention in the granular insulation layer without having an unfavorable impact on the performance of the rigid and impermeable insulation layer that supports it. In addition, the delayed release of the amount of water retained in the granular insulation layer, whether this be by streaming or evaporation, contributes to maintaining a moderate temperature on the outside partitions of a thus equipped structure and, particularly in tropical climates having rapid alternation of precipitation and strong sunlight, makes possible a natural climate control of the structure's environment. The granular insulation layer also contributes, depending on its nature, to fixing on certain pollutants contained in the rainwater and makes it possible to improve the quality of wastewater. Even by use in dry climates, the granular insulation layer makes it possible to increase the overall thermal inertia of the insulation device according to the invention and therefore to improve its performance. Preferably, the granular insulation in divided form that is used comprises expanded clay balls that can have, depending on their finishing, either good porosity or an impermeable surface. In addition, the density of the expanded clay balls is relatively low, on the order of 500 kg/m³, which makes it possible to use them on roofing without excessively weighing down the cover and makes it unnecessary, under certain conditions, to consolidate or modify the existing carrying structure. Alternatively, volcanic materials such as pumice stone or pozzolan can be used, in the form of grains or gravel.

Advantageously and according to the invention, the granular insulation is contained in at least one synthetic textile bag. The synthetic textile has the advantage of being non-porous and therefore able to stand the test of time and face the elements (rain, snow, etc.) and therefore to prevent the granular insulation in divided form from expanding.

Advantageously and according to the invention, the synthetic textile is a non-woven synthetic textile, in particular a needle-bonded geotextile. So as to be able to keep the granular insulation layer in position, in particular on vertical partitions such as walls or structures having a non-zero slope such as roof sections, the insulation device according to the invention calls for using non-porous synthetic textile bags, woven or non-woven, for example made of polypropylene needle-bonded geotextile felt, which offer the advantage of being naturally porous and of being able to be easily made in numerous dimensions by folding and heat-sealing the edges between them. Of course, any other textile that is woven or not can be used, provided that it can be closed by sewing, bonding, heat-sealing, etc. Likewise, if it is preferable that the textile used be naturally porous, an impermeable textile can be used by producing—on its surface—perforations making it possible for water to enter toward the granular insulation.

Advantageously and according to the invention, each bag has an essentially cylindrical shape, with an axis defining an installation orientation and a diameter that is smaller than or equal to the distance between the outer surface of the insulation layer and the cladding plate. The simplest shape for the bags containing the granular insulation layer is in the shape of essentially cylindrical flanges that are obtained by folding a textile rectangle along its length and sealing its long edges to one another. One of the short edges is then closed by heat-sealing, and the bag is then filled by granular insulation. Preferably, the bag is filled to only 80% to allow its flattening against the rigid insulation layer during the installation.

Advantageously and according to the invention, each bag has an essentially parallelepiped shape and comprises partitions, so-called separation partitions that are rectangular, parallel, and uniformly-spaced and whose long edges define an installation orientation and are attached to the main surfaces of each bag so as to keep between said main surfaces a distance that is less than or equal to the distance between the outer surface of the insulation layer and the cladding plate. In this embodiment, the bags come in the form of rectangular cushions whose thickness is kept essentially constant by intermediate partitions. The bags are made from two rectangles between which the separation partitions that form parallel cavities are sealed and whose edges parallel to the partitions are sealed between them and one of the perpendicular edges. The bags are then filled by the edge that is perpendicular to the partitions and that is not yet sealed in such a way as to distribute essentially equally the granular insulation in the cavities, and then the bag is closed by heat-sealing of the last edge.

Advantageously and according to the invention, at least a part of the textile partitions of each bag is perforated. Even if the geotextile felt used for producing the bags is naturally porous, it is preferable to make additional perforations so as to promote the intake of rainwater into the granular insulation layer. Preferably, it is the surface of the bag opposite the cladding plate that is perforated in the case of a parallelepiped bag.

Advantageously and according to the invention, each bag is attached to the rigid insulation layer in such a way that its installation orientation is orthogonal to a greater pitch line of the insulation layer. So as to prevent excessive packing of the granules of the insulation under the action of gravity, the bags are attached to the rigid insulation layer in such a way that their largest dimension is orthogonal to the pitch line of the partition. Thus, for a wall or a roof, the axis of the cylindrical bags or the direction of the partitions for separation of the parallelepiped bags is in general horizontal to keep the granular insulation from being packed down at one end of the bag.

Advantageously and according to the invention, the rigid insulation layer comprises on its outer surface an anti-sink coating to which the spacers are attached. So as to prevent a perforation of the rigid insulation layer, either by the weight transmitted by the spacers or by the actions and movements of the workers during the installation of the insulation device according to the invention, it is preferable to provide an anti-sink coating to the surface of the insulation of the rigid insulation layer. Such a coating is often integrated upon the manufacturing of the insulation that is delivered bonded to a surface with a rigid plate ensuring the rigidity and the anti-sink protection of the insulation. In the case where the anti-sink coating is not part of the rigid insulation layer from the outset, it can be added in the form of a sheet-metal plate, preferably solid, or laminated bonded to the insulation to form the rigid insulation layer.

Advantageously and according to the invention, the spacers are attached to the rigid insulation layer with a predetermined span along parallel lines. The spacers are attached along lines that are orthogonal to a greater pitch line of the insulation layer. The spacers are preferably made in the form of rectangular parallelepipeds made of folded perforated sheet metal, comprising, if necessary, a main surface that is partly open. The spacers are placed in a uniformly-spaced manner, in parallel lines, orthogonal to the greater pitch line of the partition to which the rigid insulation layer is attached. In general, for vertical walls or roof sections, the spacers are aligned horizontally.

Advantageously and according to the invention, on each line, the spacers are offset by a half-step between two adjacent lines. They are attached by their longest lateral surface to the anti-sink coating of the rigid insulation layer by any suitable means, for example by bonding, screwing, riveting, or any combination of these means.

Advantageously and according to the invention, the spacers of the same line are connected to one another by small U-shaped beams that cover said spacers. According to an advantageous characteristic, the cladding plate is attached to the small U-shaped beams. So as to keep the cladding plate at a distance from the rigid insulation layer and to reinforce the resistance of the insulation device according to the invention, the spacers are made integral with one another by small U-shaped beams, preferably made of folded perforated sheet metal and comprising two wings that are separated by a core with a suitable inside width to allow the two wings of the U to cover each spacer. The minimum length of the small beams is adapted so that each small beam can cover at least partially a spacer at each end of the small beam. The mounting of the small beams is preferably carried out without overlapping in such a way that the outside surface of the core of each small beam is in a plane that is common for each partition. It is thus possible to place perforated cladding plates on the small beams and to attach them in a simple manner, for example by means of blind rivets passing through the perforations of the cladding plate and of the small beam.

Advantageously and according to the invention, the cladding plate is adapted for receiving cover accessories that are adapted to be attached to said cladding plate. The rigid and perforated cladding plates make it possible to attach devices such as photovoltaic solar panels or fluid circulation panels directly onto the roof sections and/or onto the walls and to guide their cables or connecting lines. Likewise, fluid circulation coils can be simply hooked onto the perforated cladding plates, for example by means of clamps, in such a way as to constitute a heating network for the purpose of accelerating the melting of a layer of snow deposited on the cladding. Other accessories, for example networks of light points, can thus be placed on vertical walls for forming display and/or lighting elements.

The object of the invention is also a method for thermal insulation of a partition using the device. According to this method:

-   -   A first surface, a so-called contact surface, of a rigid and         impermeable insulation layer, is attached to said partition,     -   Spacers are attached to a second surface, a so-called outer         surface, of the rigid insulation layer opposite to the contact         surface, with a predetermined span along lines that are parallel         and orthogonal to a greater pitch line of the partition,     -   The spacers of the same line are connected to one another by         small U-shaped beams, in such a way that said small beams cover         the spacers, and     -   A rigid and perforated cladding plate is attached to said small         beams in such a way as to form an air gap between said cladding         plate and the outer surface of the rigid insulation layer,         characterized in that before attaching the cladding plate, bags         of granular insulation in divided form are attached between each         line of spacers to the outer surface of the rigid insulation         layer.

Advantageously and according to the invention, the spacers are offset by a half-step between two adjacent lines. Thanks to this offset, the circulation of air in the roof is improved.

Advantageously and according to the invention, each bag is placed in such a way that its largest dimension is parallel to the lines of spacers.

The invention also relates to a method and a thermal insulation device characterized, in combination, by all or part of the characteristics mentioned above or below.

Other objects, characteristics, and advantages of the invention will emerge based on the following description and accompanying drawings in which:

FIG. 1 is a cutaway view of the insulation device according to the invention;

FIG. 2 is a perspective view showing the placement of the spacers and small beams of an insulation device according to the invention;

FIG. 3 is a perspective view showing the placement of bags of granular insulation according to the invention;

FIG. 4 is a perspective cutaway view of a granular insulation bag according to one of the variants of the invention.

The thermal insulation device 2 shown in FIG. 1 is designed to insulate one partition 1 of a building (wall, sloped roof, or flat roof, etc.) by an attachment applied to the surface of this partition rotated toward the outside of the building. The device 2 comprises a rigid and impermeable insulation layer 3 that is attached to the partition 1 by a contact surface 31. In its thickness, the rigid and impermeable insulation layer 3 consists of, for example, at least one stratum 33 of insulation material such as expanded polystyrene or expanded polyurethane. These materials are in general in the form of foam with closed cavities making them impermeable to water. They also have good inherent rigidity, even if they are sometimes fragile. Based on the desired heat resistance and/or, as described below, on the nature of the partition 1, the thickness of the insulation material is variable and can be formed by multiple strata of insulating material bonded to one another.

The rigid insulation layer 3 also comprises an anti-sink coating 34 in the form of a laminated plate or a sheet-metal plate, preferably solid. This coating 34 is generally bonded at the factory onto a surface of the thickness of the insulation material to make it possible for it to have additional resistance to bending and to prevent the insulation material from deteriorating during construction site handling. In the contrary case, the coating 34 can be bonded to the insulation material strata on the construction site. For this purpose, it is possible to use a pre-painted steel sheet with a thickness of 0.75 to 1 mm or a laminated sheet with a thickness of 8 to 12 mm. The rigid insulation layer 3 can consist of a number of rectangular plates that are juxtaposed for covering the surface of the partition 1. On their edges, these plates can comprise assembly means such as a tongue.

Based on the partition to be insulated, three main cases can be considered: the thermal insulation device 2 is attached to a vertical partition such as an outside wall, or to a sloped partition such as a roof section. In this latter case, it is possible to use the insulation device according to the invention right on the frame or on a roof that is already made when the latter is made of sheet metal, for example formed by steel compartments.

In the case of an attachment to a vertical wall, the rigid insulation layer 3 is preferably bonded to the wall by glue beads, for example expanding foam if necessary aided by attachment plugs. Other attachment methods, known by one skilled in the art, for insulation from the outside can also be used provided that they make possible an adequate hold of the insulation on the wall. When the insulation device according to the invention is placed on the roof, it is advisable to remove the cover if the former does not make it possible to position the device on a flat surface (tiles, corrugated sheet metal, etc.). In this case, it is preferable to place a vapor-barrier screen directly on the existing frame and, for example, to hold it there by nailed battens. The insulation layer 3 is then bonded to the battens. In some cases, it is possible to preserve the existing roof, for example when the former consists of flat sheets comprising stiffeners of trapezoidal cross-section (steel compartments) at regular intervals. In this case, it is possible to bond between the stiffeners a first stratum of insulation material, with a thickness that is approximately equal to the height of the former for forming a flat surface. The placing of the rigid insulation layer 3 is then completed by bonding on this stratum a second stratum of insulation material comprising the anti-perforation coating 34.

Once the rigid insulation layer 3 is attached to the partition 1, spacers 4 of a generally parallelepiped shape (rectangular parallelepiped) are attached to its outer surface 32 (which is also the outer surface of the anti-perforation coating 34). These spacers 4 are made of, for example, perforated sheet metal that is painted and formed by folding and riveting. These spacers 4 are attached by, for example, bonding and/or riveting and/or screwing to the anti-perforation coating 34 by inserting, if necessary, a reinforcement plate 13 (FIG. 2).

The spacers 4 are attached on their surfaces corresponding to the thickness and to the length of the parallelepiped, in a uniformly-spaced manner along a span P, in alignment according to the length of the spacer along lines that are orthogonal to the slope of the partition 1. Thus, for straight walls or uniform roof sections, the spacers 4 are aligned according to the horizontal lines that are themselves uniformly spaced between them.

By way of example, the spacers 4 measure 250 mm long, 150 mm wide, and 70 mm thick. They are placed along a span of 600 mm on a horizontal line and offset by a half-step on the adjacent lines. The spacing between lines of spacers is also on the order of 600 mm, although this is not absolutely necessary; these dimensions can vary based on calculations of resistance and regulations regarding snow and wind that are applicable to the building.

The spacers 4 are made integral along lines of spacers by small beams 5 comprising a core 5 a and two wings 5 b retracted orthogonally to the core for forming a U-shaped profile. The width of the core 5 a of each small beam is adapted so that the former can cover the surface of the spacers opposite to the surface for attachment of the former and so that the wings 5 b of the small beam extend toward the attachment surface by framing the spacer. The length of the small beams 5 is preferably equal to an integer of span P, in general two or three, with a lower-value tolerance in such a way as to prevent any overlapping of one small beam on the adjacent small beam. The length of the small beams is also to be enough so that each end overlaps the spacer that it covers over at least 50 mm. The small beams are attached to the spacers by blind rivets placed through the wings of the small beams and main surfaces of the spacers that they cover in such a way as not to create rough spots on the surface of the cores of the small beams so as to be able to attach a rigid and perforated cladding plate 6 there at a predetermined distance from the rigid insulation layer 3 corresponding to the width of the spacers 4.

The cladding plate 6 is preferably made by means of painted perforated sheet-metal plates placed supported on the small beams 5 and attached to the former by means of blind rivets. Preferably, there is a rivet on each spacer and a rivet on the core of the small beam between each spacer pair. The cladding plate 6 is rigid enough to withstand forces exerted by a possible layer of snow (essentially on the roof) or by the wind (particularly on the walls). The cladding plate 6 is also perforated in such a way as to allow air to pass through perforations so as to prevent heating such as can be found on solid sheets.

In addition, the use of a rigid and perforated cladding plate 6 makes possible the flow of rainwater at least in part through the plate and also makes it possible to use perforations to simply attach accessories 17 to this plate. By way of example of accessories that can thus be easily attached, it is possible to cite photovoltaic or hot-water (solar water-heating) solar panels as well as their cables or connecting lines. In cold climates where the plates 6 are likely to be covered with snow, it is possible to attach snow guards to prevent snow slides around roofs or else coils for circulation of a heat transfer fluid to accelerate snow melt. Other accessories can also be easily installed, such as, for example, light strings or light-emitting diodes forming an advertising display screen.

According to an advantageous characteristic of the thermal insulation device according to the invention, a layer 8 of granular insulation material 9 in divided form, for example in the form of balls, grains, gravel, not connected to one another, is inserted between the outer surface 32 of the rigid insulation layer 3 and the cladding plate 6. Preferably, the thickness of this granular insulation layer 8 is limited to two-thirds of the spacing existing between the outer surface 32 of the rigid insulation and the cladding plate 6 so as to leave a free space making it possible to maintain an air gap 7 under the cladding plate 6.

The granular insulation 9 can preferably consist of expanded clay balls, which may or may not be porous, or else granules of pumice stone or pozzolan. So as to keep this granular insulation in place, it is placed in preferably parallelepiped bags 10 made of a non-woven synthetic textile, for example polypropylene geotextile needle-bonded felt. Such a textile has the advantage of being naturally porous and of being able to be assembled by heat-sealing. Of course, any other textile—whether it be woven or not—can be used, provided that it can be closed by sewing, bonding, heat-sealing, etc. Likewise, if it is preferable that the textile used be naturally porous, an impermeable textile can be used by producing—on its surface—perforations making it possible for water to enter toward the granular insulation.

Such a bag 10 is illustrated in perspective intersected by a median plane as in FIG. 4 and comprises two main rectangular surfaces 14 a and 14 b placed opposite one another and whose respective edges are heat-sealed to one another for forming a closed bag. The main surface 14 a is in addition perforated in such a way as to make possible a direct intake of rainwater. Between the main surfaces 14 a and 14 b, rectangular separation partitions 11 are placed parallel to one another and sealed to the two main surfaces by a flap 15 formed on their long edge so as to define cavities 16. The width of the separation partitions 11 is provided to keep the thickness of the layer 8 of granular insulation 9 essentially constant. The filling of the cavities 16 of the bag 10 is carried out by one of the edges that are orthogonal to the separation partitions, and then the edge is closed by heat-sealing edges opposite the main surfaces.

The dimensions of the bags 10 are provided to be multiples of the span P for the length so as to place them parallel to the lines of spacers 4 supported on at least two spacers and for corresponding to the spacing between two lines of spacers for the width. The bags 10 are attached to the outer surface of the rigid insulation layer 3 by glue beads 12, parallel to the lines of spacers. The bags 10 are arranged in such a way that the direction of the separation partitions 11, which also defines the largest dimension of the cavities 16, is parallel to the lines of spacers 4 (and therefore perpendicular to the greater pitch line of the partition on which the insulation device is placed) in such a way that the length of the cavities 16 is also orthogonal to this greater pitch line (see FIG. 3).

By way of example, the dimensions of a bag 10 adapted to the thermal insulation device whose dimensions were given above are on the order of 600, 1200 or 1800 mm long, 600 mm wide, and the constant thickness maintained by the separation partitions 11 is on the order of 100 mm.

As a variant, the bags 10 can be made of a single cavity formed by a cylindrical casing obtained by folding a geotextile felt sheet on itself and sealing its edges in such a way as to form a cylinder with a length of one, two, or three spans P and a diameter that is approximately equal to the distance existing between the outside surface 32 of the rigid insulation layer 3 and the cladding plate 6. So as to form the air gap 7 below the former, the cylindrical bag is filled to only 80% of its capacity, making possible its flattening on at least two glue beads 12 to obtain an oblong cross-section whose small diameter corresponds to the desired thickness of the granular insulation layer 8. In this variant embodiment, the cylindrical bags are arranged in such a way that the axis of the cylinder (which corresponds to the largest dimension of the single cavity) is parallel to the lines of spacers 4, with multiple bags being used to fill the spacing between two lines of spacers. Of course, the bags 10 can be arranged in parallel rows or staggered, each bag resting on two other bags.

Thanks to the presence of this granular insulation layer, the thermal inertia of the insulation device and therefore of the building that is insulated with this thermal insulation device is improved. In addition, the rainwater reaching the cladding plate 6 passes through it at least in part owing to its perforations and reaches the granular insulation layer 8 in which it is temporarily trapped. The streaming of the rainwater is thus slowed, minimizing the risks of clogging from rain drainage. In addition, in the event of fast alternation of precipitation and sunlight, the evaporation of trapped water creates a phenomenon of local climate control.

Of course, this description is provided by way of illustrative example only, and one skilled in the art could provide numerous modifications thereto without exceeding the scope of the invention, such as, for example, modifying the dimensions and the arrangement of the spacers and bags of granular insulation to adapt to the geometry of the building to be insulated. Likewise, the accessories that can be attached to the cladding plate 6 are not limited to the devices described above, with the perforations of the cladding plate also able to make it possible to attach a thatched roof covering, for example. 

1. Device (2) for thermal insulation from the outside of a building partition (1), in particular applicable to walls and to roofs, comprising: A rigid and impermeable insulation layer (3) comprising a first surface, a so-called contact surface (31), suitable for being attached to said partition, and a second surface, a so-called outer surface (32), opposite to the contact surface, A rigid and perforated cladding plate (6), Spacers (4) attached to said outer surface and adapted to hold said cladding plate at a distance from the outer surface and to form an air gap (7) between said cladding plate (6) and the outer surface (32) of the rigid insulation layer (3), A layer (8) of granular insulation between the rigid insulation layer (3) and the cladding plate (6), wherein the granular insulation (9) is in divided form and contained in at least one synthetic textile bag (10).
 2. Insulation device according to claim 1, wherein the synthetic textile is a non-woven synthetic textile, in particular a needle-bonded geotextile.
 3. Insulation device according to claim 1, wherein the granular insulation (9) is a porous granular insulation.
 4. Insulation device according to claim 1, wherein each bag (10) has an essentially cylindrical shape, with a diameter that is less than or equal to the distance between the outer surface (32) of the rigid insulation layer (3) and the cladding plate (6).
 5. Insulation device according to claim 1, wherein each bag (10) has an essentially parallelepiped shape and comprises partitions, so-called separation partitions (11) that are rectangular, parallel, and uniformly spaced and whose long edges are attached to the main surfaces (14 a, 14 b) of each bag so as to keep a distance that is less than or equal to the distance between the outer surface (32) of the rigid insulation layer (3) and the cladding plate (6) between said main surfaces.
 6. Insulation device according to claim 1, wherein at least one part of the textile partitions of each bag (10) is perforated.
 7. Insulation device according to claim 1, wherein the rigid insulation layer (3) comprises an anti-sink coating (34) on its outer surface (32), to which coating the spacers (4) are attached.
 8. Insulation device according to claim 1, wherein the spacers (4) are attached to the rigid insulation layer (3) with a predetermined span (P) along parallel lines.
 9. Insulation device according to claim 8, wherein the spacers are offset by a half-step between two adjacent lines.
 10. Insulation device according to claim 8, wherein the spacers (4) of the same line are connected to one another by small U-shaped beams (5) that cover said spacers.
 11. Insulation device according to claim 10, wherein the cladding plate (6) is attached to the small U-shaped beams (5).
 12. Insulation device according to claim 1, wherein the cladding plate (6) is adapted to receive cover accessories (17) that are adapted to be attached to said cladding plate.
 13. Method for thermal insulation of a building partition (1) from the outside, according to which: A first surface, a so-called contact surface (31), of a rigid and impermeable insulation layer (3), is attached to said partition (1), Spacers (4) are attached to a second surface, a so-called outer surface (32), of the rigid insulation layer (3) opposite to the contact surface, with a predetermined span (P) along lines that are parallel and orthogonal to a greater pitch line of the partition, The spacers (4) of the same line are connected to one another by small U-shaped beams (5), in such a way that said small beams cover the spacers, and A rigid and perforated cladding plate (6) is attached to said small beams (5) in such a way as to form an air gap (7) between said cladding plate (6) and the outer surface (32) of the rigid insulation layer (3), wherein before attaching the cladding plate (6), bags (10) of granular insulation (9) in divided form are attached between each line of spacers (4) to the outer surface (32) of the rigid insulation layer (3).
 14. Insulation method according to claim 13, wherein the spacers (4) are offset by a half-step between two adjacent lines.
 15. Insulation method according to claim 13, wherein each bag (10) is placed in such a way that the largest dimension of the cavity or cavities that form(s) it is parallel to the lines of spacers.
 16. Insulation device according to claim 2, wherein the granular insulation (9) is a porous granular insulation.
 17. Insulation device according to claim 2, wherein each bag (10) has an essentially cylindrical shape, with a diameter that is less than or equal to the distance between the outer surface (32) of the rigid insulation layer (3) and the cladding plate (6).
 18. Insulation device according to claim 2, wherein each bag (10) has an essentially parallelepiped shape and comprises partitions, so-called separation partitions (11) that are rectangular, parallel, and uniformly spaced and whose long edges are attached to the main surfaces (14 a, 14 b) of each bag so as to keep a distance that is less than or equal to the distance between the outer surface (32) of the rigid insulation layer (3) and the cladding plate (6) between said main surfaces.
 19. Insulation device according to claim 3, wherein each bag (10) has an essentially parallelepiped shape and comprises partitions, so-called separation partitions (11) that are rectangular, parallel, and uniformly spaced and whose long edges are attached to the main surfaces (14 a, 14 b) of each bag so as to keep a distance that is less than or equal to the distance between the outer surface (32) of the rigid insulation layer (3) and the cladding plate (6) between said main surfaces.
 20. Insulation method according to claim 14, wherein each bag (10) is placed in such a way that the largest dimension of the cavity or cavities that form(s) it is parallel to the lines of spacers. 